Look to the lights. Here's the same garden shown in the first photo, at dusk. Sandy used five different light sources here, including the barn light fixtures above (attached to a conduit running across the pergola), strings of big lights on a sensor timer that turn on at dusk, and vintage lanterns that have been rewired to low voltage for use outside.
Sandy advices to be experimental with your light sources, and don't be afraid to keep adding new elements to get the right glow for different times of the night or evening.
